Manti Te'o mystery: How do you fall in love with someone you've never met?

He describes his relationship with a woman he met online as “emotional” and “authentic,” and called her the “love of his life.”

Yet as the bizarre story unravels of Notre Dame star linebacker Manti Te’o and the supposed death of the girlfriend he apparently never met face to face (he says he was the victim of hoax that invented her identity), many people are wondering how somebody could carry on such a meaningful relationship without ever sharing the same room -- much less a kiss.

“We maintained what I thought to be an authentic relationship by communicating frequently online and on the phone, and I grew to care deeply about her,” Te’o said in a statement Wednesday.

That part of his story, at least, is not all that unusual. For people who have not participated in dating websites, or who met their partner in a traditional setting like a party, the notion of online love may be hard to grasp. But many relationships these days develop through the Internet: a 2010 Match.com survey says that 17 percent of couples married in the last three years met online.

“People probably think this never happens,” says Dr. Gail Saltz, a TODAY contributor and psychiatrist who specializes in relationships and sex. “The huge change in our social activity based solely on the Internet has made this a phenomenon that does happen.”

Although some people may find it easier to be intimate online than in person, Saltz cautioned that online relationships that don’t progress to the face-to-face kind are “gravely, gravely limited.” Among the things they lack are sex, physical intimacy and non-verbal communication through body language, she said.

“Togetherness is hugely important because you have to be able to experience more than an idealized version of this person,” Saltz said.

Still, she said, it is possible for someone to feel in love without ever being in the same room as their beloved, much the way people develop strong crushes on celebrities.

“Love is a subjective experience,” Saltz said. “I can’t tell that person they’re not in love. But the person they think they’re in love with may or may not be the person they’re communicating with.” People present the best version of themselves online, more than is possible in real life, she said.

“Obviously it is very possible for both people to delude themselves that they know the other person,” Saltz said. “People want to be in love. In some ways it’s easier to fall in love with someone when you only get bits and pieces of them because you can imagine the rest.

“Maybe that person is all that you imagine them to be, but until you have spent a lot of time with that person and experience them, warts and all, you don’t know if that’s really who they are,” she said. “It’s not really a test of the longevity of a relationship.”

Dr. John Grohol, a psychologist who has studied online dating, says people can develop an emotional attachments online just as they do in the early stages of dating.

“The stories and the identifying with one another, those things can happen because they happen in the brain, intellectually and emotionally, and they can happen whether you read a written word or hear someone saying that word,” he said. “Words can be very powerful, even when written, they can evoke emotion.”

But he noted that the online talk is usually “setting the foundation” to see if two people like each other.

“It’s perfectly possible to have a romantic relationship online and not meet the person for a very long time,” Grohol said. “But I do think it’s inevitable, normal for people to eventually meet face to face. If that never happens there would have to be a really good reason.”

Most people do want a physical relationship, he said, and he recommended that online partners meet within a year. Sometimes people take their time for reasons like physical distance or a disability.

“Usually it doesn’t go too far but there have been people that have waited months or even longer before they’ve met face to face and just use email, chat and telephone calls to do it."

Though the full truth about Te’o's relationship may never come out, there are various reasons why a person would maintain an online relationship without real-world contact. They include fear of intimacy, fear of abandonment, fear of commitment, or perhaps not having time to invest in a relationship, Saltz said.

Grohol said he would urge caution if an online partner would not share more than one photo, refused to video chat or talk about the intimate details of their lives.

Saltz said there is nothing wrong with online dating, noting that it’s leading to more and more marriages.

“But you should understand that until you’ve been with the person, what you are experiencing may be wholly true or only part of the package,” she said.